Authoritative
Definition 1 of 2

Trustworthy Experts
Use 'authoritative' when referring to people or texts respected for their deep knowledge.

She is an authoritative figure in child psychology.
Not Always Right
'Authoritative' doesn't mean infallible; even reliable sources can be questioned.

Despite the study's authoritative reputation, its findings were later challenged.
Subject-Specific
An 'authoritative' source is especially knowledgeable in a particular subject or field.

The book is considered an authoritative work on European history.
Compare with
authenticcommandcredibledecisivedominatrixexpertpowerfultrustworthy
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